Interlock for elevator doors



June 23,1942. E, FENN 2,287,751

INTERLOCK' FOR ELEVATOR DOORS Filed Sept. 27, 1940 2 Sheets-Sheet lEMORY W FENN INVENTOR- F12" PER ATTORNEY June 23, 1942. I .-w. FENN2,287,751

INTERLOCK FOR ELEVATOR DOORS Filed Sept. 27. 1940 2 Sheets-Sheet 2 EMORYW FENN /NVENTOR ER ATTORNEY Patented June 23, 1942 I UNITED STATESPATENT OFFICE 2,287,751 INTERLOOK FOR ELEVATOR DOORS Emory W. Fenii,Chicago, 111.

Application September 27, 1940, Serial No. 358,693

12 Claims. (01. 1s7 s1) This invention relates to an improved interlockfor a vertical sliding elevator and dumbwaiter door and has, for one ofits principal objects, the provision of a device which will not allowthe elevator door to be opened unless the car is at the station wherethe goods or. passengers are to be removed from the elevator.

One of the important objects of this invention is the provision of adoor interlocking device for freight elevators and dumb-waiters whichwill make the operation of the doors simple and yet fool proof, becauseof simplicity of design and small number of parts.

Another important object resides in the provision of an automatic doorreleasing device for elevators and the like.

3 A further object is the provision of a door interlocking and safetydevice which will open the elevator control circuit when any one of thestation doors to the shaft is opened.

One object of the invention is to provide, in connection with anelevator system, means whereby none of the doors in the system can beopen while the elevator is traveling. Thisprevents so-called stealingthe elevator, and in some buildings, like larger apartment houses, thestealing of groceries and the like which may be sent up in elevators ofthe dumb-waiter type.

Another important object is to provide, in an interlock for elevators, aconstruction whereby every part including the base plate isinterchangeable whereby the same can be used either on right or lefthanded devices or in cases where the door opens on upward movement or ondownward movement.

A still further object of the invention lies in the provision of asafety device which, while automatic in nature, requires a minimumamount of maintenance.

Other and further important objects of the invention will be apparentfrom the disclosures in the accompanying drawings and followingspecification.

The invention, in a preferred form, is shown in the drawings andhereinafter more fully described.

In the drawings: j

Figure 1 is a front elevation of the device of this invention with thedoor locked into a closed position.

Figure 2 is a top plan view of the structure of Figure 1, showing acut-away portion of the elevator and door.

Figure 3 is a front elevation of the device of and the operatingmechanism in its normal position while the elevator is being operated.

Figure 4 is a front view of a cut-away portion of the device showing theinterlocking mechanism when the door at the station lowers to openinstead of raising as in Figures 1 and 3.

Figure 5 is a cut-away portion of the device of Figure 3, showing therelationship of certain elements when the door is open.

Figure 6 isa detailview showing the device when the door has beennormally opened.

As shown in the drawings: 7 The reference numeral 8 indicates generallythe assembly plate which contains holes 40 that permit the fastening ofthis device to the proper location in the elevator shaft. The box l0contains the electricalcontrol switch and is bolted to the assemblyplate 8. The rectangular bar I2 which is slidably mounted on the pin I4,is normally held against the key or cotter pin l6 by the spring 18.

When the circuit is closed as shown in Figure 1, the rectangular bar I2,which may be made of any electrical conducting material, is caused tocontact the terminals 20 and thus provide a complete circuit for thepassage of current. Therefore, with the switch or circuit breakerclosed, the dumb-waiter or elevator is ready to be moved to anypredetermined station. These terminals .20, to which the control circuitwires (not shown) may be attached, are mounted on an insulating block22. The numeral 38 indicates a connector used to grip an electricalcable which contains wires that connect the terminals 20.

The element 24, to which the pin I4 is secured, is made of anynon-conducting material such as fiber, mica or the like. This element 24.is fastened to the upper part of the rod 26 by the screws 28. .The boxI!) is completely enclosed with a tight fitting cover 42 shown brokenaway in Figure 1. The built-up portions are an integral'part of the boxIt], and one of these provides a seating means for the coiled spring 46.These built-up portions are at either lower corner so the box may beused for either right or left-hand camsv32; that is, the box may be usedon the right or left side of the shaft, depending on the position of thecam on the elevator.

A flat ribbed plate 48, which operates within the forked end of thehold-up lever arm 52, is fastened to the door 30 in some suitable mannersuch as by the fiat L-shaped iron 50, which is secured to the door bythe bolt 54. The hold-up this invention with the door in a closedposition lever arm 52 pivots about the bolt 56, whenever the door 30 isopened or closed. When the door 30 is closed, the fiat ribbed plate 48contacts the straight prong 58 of the forked lever arm 52, and in sodoing, gives it a counter-clockwise rotation which causes the rod 26 andthe rocker arm 60 to be forced to their relative normal positions asshown in Figure 3. The rod 25 pivots slightly about the bolt 62. Thebolt 62 holds the lever arm 52 pivotally in contact with the rod 26. Thebolt 55 holds the lever arm 52 pivotally secured to the assembly plate8. When the door 30 is closed, the lever arm 52 contacts the rocker arm60 and raises it to its normal position against the spring 46 and inreadiness for operation. The rocker arm 60 is pivotally fastened to theplate 8 by the bolt 66.

A two-piece extension it with its sections Ma and 14b rotatably securedto each other at 68 is adjustably fastened at 10 to the arm 66 by thebolt 12. A roller 36 is rotatably mounted on the extension arm Na by thebolt 15. There are projections l8 and ill] on each section of theextension arm Ma and 74b respectively and are adapted to retain thespring 82 in its proper relationship to these projections. The spring 82urges the section Ma into its normal position against the lug Me whichis integral with the section Mb. The spring 82 is sufficiently heavy toprevent any relative folding of the sections Ma and 14b such as might beencountered when the roller 36 is resting against the cam 32 and therocker arm 50 is in the position shown in Figure 1. However, when therocker arm 50 and rod are in the position shown in Figure 5, theextension arm 14 assumes a position of angularity relative to its normalposition and causes the periphery of the roller 36 to extend to theright to contact the face of the cam 32. Since one prong 84 .of the rod26 is engaged in the wedge-shaped slot 86 of the rocker arm 50, thesection Ma of the extension arm 14, which is pivoted about the point 68,will be made to co-act with the elevator cam whenthe car passes.

Figure 4 exemplifies the arrangement of the mechanism in this devicewhen the elevator shaft door lowers to an open position. Thisillustration shows the door locked. The principle of this mechanism is,of course, the same as for the device of Figure 3 where the door israised to an open position. The parts used in this device aresubstantially the same with .only. a slight modification as can be seenin the drawings. The lever arm 53 is pivotally secured to the plate 8 bythe bolt 51. It will be noted that when the door raises, the pivotalpoint of the hold-up lever arm is at 55 (Figure 3), but where the doorlowers to open, the pivotal point is at 5'? (Figure 4). The offset rod21 is rotatably fastened to the lever arm 53 by the. bolt 63. In itsnormal position, the hold-up lever arm 53 is raised to a substantialhorizontal position and at right angles with the rod 21. The lever arm53 coacts with the projection 55 of the. rocker arm 6! to hold it in theposition shown in Figure 3.

To best explain the functioning and operation of this device, it will benecessary to assume that the door may often be in divers positions andthe relative action of the mechanism at such times will be considered.In Figure 3, the device is shown in its normal closed position, and inthis position, the electrical circuit is kept closed through theoperation of the rod 25 which is pivoted to the hold-up lever arm. Thislever arm contacts the rocker arm and holds it and accordingly theroller to the proper distancefrom the elevator cam. In its normalposition, the elevator cam never contacts the roller in its passing upand down the shaft. This means a silently operated elevator.

When the elevator stops at a position with the cam opposite the roller,but a predetermined distance from it as shown in Figure 3, the door tothe shaft may be opened. In opening the door, the lever arm freelyrotates in a clockwise direction and, in so doing, allows the rocker armwhich it was holding, to pivot downwardly, aided by the spring 48 andthe weight of the arm, into the position shown in Figure 5. During thisoperation, the rod 25, which is pivoted to the lever arm, also dropsdownwardly into the position shown in Figure 5. As shown in thedrawings, particularly Figures 3 and 5, the rocker arm cannot pivotdownwardly in a clockwise rotation beyond the position shown in Figure 5when the elevator cam is opposite the roller. This allows for freemovement by the bifurcated rod 25.

If there is an attempt to open the door from its normally closedposition when the elevator is not opposite the roller, the lever armwill be moved from its horizontal position in Figure 3 to an angularposition shown in Figure 1. This movement of the hold-up lever arm willallow the rocker arm to pivot in a clockwise direction, beyond theposition shown in Figure 5 where the roller hits against the cam,because there is no cam present to prevent its pivotal movement to aposition beneath the rod 25 Where the element 84 engages the V-shapedslot 86. The'engagement of the bifurcated rod 26 with the rocker armprevents any further clockwise rotation of the lever arm which engagesthe flat ribbed plate 48 which is securely fastened to the door 30 andprecludes opening the door.

Since the circumference of the roller extends into the path of the cam,it might be thought that if the door is held upwardly against theelement 52a as the elevator passes, the cam will strike the roller anddisengage the rocker arm from the element 84, thus permitting the rod 26to drop to the position shown in Figure 5 and thereby allow opening ofthe door. But such is not the case because when the moving elevatorstrikes the roller 35, the element Ma merely pivots about 68 andcompresses the spring 82 leaving the prong 84 engaged in the slot 85. Itcan be seen that with this device, any attempt to open the doors to theelevator shaft when the elevator is not standing at that landing will befutile. To disengage the rocker arm, it is only necessary to lower thedoor to a completely closed position, thereby raising the rod 25 out ofthe V-shaped slot 86 and permitting the rocker arm to move out fromunder the end of the rod. The door is then again in position to beopened.

Herein is provided a device which will preclude so-called stealing theelevator, as it passes from floor to floor. Such a practice of stealingthe elevator, which may have on it groceries or other commodities is nowprevalent in hotels and apartment houses.

This invention is made to operate with a minimum number of moving parts.The parts are interchangeable and may be used for doors which open rightor left.

It must be remembered that this invention provides an interlockingmechanism which the elevator cam does not contact, if no attempt is madeto open the door and steal theelevator, when passing up and down theshaft, thereby eliminating the constant. clickingof .the elevator.

cam on the roller which all other prior types of door interlockingdevices have. This provides for a silent operating mechanism which ishighly important in hospitals and dwellings.

I am aware that many changes may be made and numerous details ofconstruction varied throughouta wide range without departing from theprinciples of this invention, and I, therefore, do not purpose limitingthe patent granted hereon otherwise than as necessitated by the priorart.

I claim as my invention:

1. Interlocks for elevator doors having an electrical circuit, a circuitbreaker, means for actuating the circuit breaker, said means comprisinga rod, a forked lever arm, a flat plate cooperating with the forked endof the lever arm, locking means for the circuit breaker and door, saidlocking means comprising a rocker arm engaging the rod, means foractuating the lock ing means, said means comprising a two-piecepivotally joined extension arm adjustably secured to said rocker arm atone end and having a roller on its opposite end. 7

2. In an interlock for elevator doors, a door, a lever arm, a circuitinterrupting arm pivotally secured to the lever arm, a rocker arm, anextension arm, said extension arm being composed of two pivotally joinedelements held in proper relationshipby a spring, and adjustably securedto the rocker arm and a cam on the elevator.

3. In an interlock for elevator doors having an electrical circuit, acam on the elevator, an assembly plate, a switch, a rocker arm, atwopiece jointed extension arm secured thereto to cooperate with theelevator cam, means for holding the switch and rocker arm in theirrespective positions, means for actuating the rocker arm, and means foractuating the switch.

4. In an interlock for elevator doors having an electrical circuit, anelevator cam, an assembly plate, a switch, a rocker arm, an extensionarm secured thereto to cooperate with the elevator cam, means forholding the switch and rocker arm in their respective positions, saidmeans including a lever arm, means for actuating the rocker arm, andmeans for actuating the switch.

5. In an interlock for elevator doors having an electrical circuit, acam in the elevator, an assembly plate, a switch, a rocker arm, anextension arm secured thereto to cooperate with the elevator cam, meansfor holding the switch and rocker in their respective positions, saidmeans including a lever arm, means for actuating the rocker arm, saidmeans comprising the elevator cam, and means for actuating the switch.

6. In an interlock for elevator doors having an electrical circuit, anelevator cam, an assembly plate, a switch, a rocker arm, an extensionarm secured thereto to cooperate with the elevator cam, means forholding the switch and rocker arm in their respective positions, saidmeans including a lever arm, means for actuating the rocker arm, saidmeans comprising the elevator cam, means for actuating the switch, saidmeans comprising a plate on the door cooperating with a forked end ofthe lever arm.

7. In an elevator system, having a number of landings and a car, a doorat each landing, interlock means at each landing for preventing openingof a door except when the car is at that landing, said means including alug on the door, a rod vertically movable in the interlock means, acircuit make and break switch controlled by the rod, and means forlocking the rod in current making position except when the. car is'at alanding, said means including a rocker :zrmhaving an end adapted toproject below the end of the vertical arm, and a lever arm operated bythe lug on a landing door for shifting the vertical arm to break thecircuit.

8, In an elevator system, having a number of landings and a car, a doorat each landing, interlock means at each landing for preventing openingof a door except when the car is at that landing, said means including alug on the door, a rod vertically movable in the interlock means, acircuit make and break switch controlled by the rod, and means forlocking the rod in current making position except when the car is at alanding, said means including a rocker arm having an end adapted toproject below the end of the vertical arm, and a lever arm operated bythe lug on a landing door for shifting the vertical arm to break thecircuit, said lever arm also operating to shift the rocker arm to lockthe vertical arm when a car is not at the land- 9. In an elevatorsystem, having a number of landings and'a car, a door at each landing,interlock means at each landing for preventing opening of a door exceptwhen the car is at that landing, said means including a lug on the door,a rod vertically movable in the interlock means, a circuit make andbreak switch controlled by the rod, and means for locking the rod incurrent making position except when the car is at a landing, said meansincluding a rocker arm having an end adapted to project below the end ofthe vertical arm, and a lever arm operated by the lug on a landing doorfor shifting the vertical arm to break the circuit, said lever arm alsooperating to shift the rocker arm to lock the vertical arm when a car isnot at the landing, and a cam on the elevator acting to lock the rockerarm in retracted position for release of the Vertical arm by the leverarm when the elevator is at a landing.

10. In an elevator system, having a number of landings and a car, a doorat each landing, interlock means at each landing for preventing openingof a door except when the car is at that landing, said means including alug on the door, a rod vertically movable in the interlock means, acircuit make and break switch controlled by the rod, and means forlocking the rod in current making position except when the car is at alanding, said means including a rocker arm having an end adapted toproject below the end of the vertical arm, and a lever arm operated bythe lug on a landing door for shifting the vertical arm to break thecircuit, said lever arm also operating to shift the rocker arm to lockthe vertical arm when a car is not at the landing, and a cam on theelevator acting to lock the rocker arm in retracted position for releaseor the vertical arm by the lever arm when the elevator is at a landing,a roller on the rocker arm adapted to normally stay out of contact withthe elevator cam and ride against the same for maintaining the rockerarm in retracted position when the door is opened at the time that theelevator is at that landing.

11. In an elevator system, having a number of landings and a car, a doorat each landing,

interlock means at each landing for preventing opening of a door exceptwhen the car is at that landing, said means including a lug on the door,a rod vertically movable in the interlock means, a circuit make andbreak switch controlled by the rod, and means for locking the rod incurrent making position except when the car is atv a landing, said meansincluding a rocker arm having an end adapted to project below the end ofthe vertical arm, and a lever arm operated by the lug on a landing doorfor shifting the vertical arm to break the circuit, said lever arm alsooperating to shift the rocker arm to lock the vertical arm when a car isnot at the landing, and a cam on the elevator acting to lock the rockerarm in retracted position for release of the vertical arm by the leverarm when the elevator is at a landing, a roller on the rocker armadaptedto normally stay out of contact with the elevator cam and ride againstthe same for maintaining the rocker arm in retracted position when thedoor is opened at the time that the elevator is at that landing, andfurther means on the rocker arm adapted to prevent release of thevertical bar by the rocker arm in the event that said bar has beenlocked against downward movement by a door opening movement when theelevator is not at that landing.

12. In an elevator system, having a number of landings and a car, a doorat each landing, interlock means at each landing for preventing openingof a door except when the car is at that landing, said means including2. lug on the door, a rod vertically movable in the interlock means,

a'circuit make and'break switch. controlled by thero'd', and'meansfor'locking the rod in current making position except when the car is ata landing, said means including a rocker arm having an end adapted toproject below the end of the vertical arm, and a lever arm operated bythe lug on a landing door for shifting the vertical arm to break thecircuit, said lever arm also operating to shift the rocker arm to lockthe vertical arm when a car is not at the landing, and a cam on theelevator acting to lock the rocker arm in retracted position for releaseof the vertical arm by the lever arm when the elevator is at a landing,a roller on the rocker arm adapted to normally stay out of contact withthe elevator cam and ride against the same for maintaining the rockerarm in retracted position when the door is opened at the time that theelevator is at that landing, and further means on the rocker arm adaptedto prevent the release of the vertical bar by the rocker arm in theevent that said bar has been locked against downward movement b a dooropening movement when the elevator is not at that landing, said meanscomprising a broken joint in the. rocker arm and a bifurcated link andspring in connection with the joint.

EMORY W. FENN.

